Prekallikrein and High Molecular Weight Kininogen Deficiency in Oman: a Challenging Diagnosis in Mucosal Bleeding

Hematology & Transfusion International Journal

Clinical Paper Open Access Prekallikrein and high molecular weight kininogen deficiency in Oman: a challenging diagnosis in mucosal bleeding

Abstract Volume 7 Issue 1 - 2019 Background: Prekallikrein (PK) and high molecular weight kininogen (HMWK) are Hanan F Nazir,1,2 Anil V Pathare3 contact factors that are involved in the intrinsic pathway of the coagulation cascade. 1Child Health Department, Sultan Qaboos University Hospital, Deficiency of PK or HMWK are known to be associated with prolonged a PTT, but Muscat, Oman no clinical bleeding. However, rare cases of PK deficiency have been reported to be 2Department of Pediatrics, Alexandria Faculty of Medicine, associated with mucosal bleeding. Alexandria, Egypt 3Department of Haematology, Sultan Qaboos University, Muscat, Objective: To report on epidemiological and clinical characteristics of Omani patients Oman with PK and HMWK deficiency, focusing on one symptomatic case. Patients and methods: We reviewed the files of Omani patients who had persistently Correspondence: Hanan Fawzy Nazir, Child Health prolonged a PTT that proved to be secondary to PK or HMWK deficiency over a Department, SQUH, Alkhoudh, Muscat 123, PO Box 38, Oman, Tel +968 24 144110; +96896556198, Fax +968 24141136, period of ten years. Email Results: Eight cases (three with PK, five with HMWK deficiency) were identified. All but one case were asymptomatic. A thirteen year-old female with Hashimoto thyroiditis Received: January 29, 2019 | Published: February 27, 2019 who presented with easy bruising, severe prepubertal vaginal bleeding and recurrent hematemesis proved to have prekallikrein deficiency. Acquired vWD, coagulation factors deficiency, lupus anticoagulant, platelet dysfunction were ruled out. No local cause of bleeding could be identified even after four endoscopic examinations, Meckel’s diverticulum scintigraphy and CT angiography of the abdomen. Conclusion: PK and HMWK are underestimated in Oman. Most cases were incidentally detected. They significantly impact medical costs, related to extensive laboratory testing and undue delay in planned surgical procedures. Some cases with clinical bleeding impose a diagnostic challenge.

Keywords: contact factors deficiency, high molecular weight kininogen, oman, prekallikrein, prolonged aPTT

Abbreviations: PK, Prekallikrein; HMWK, High Molecular The objective of the current work is to report on epidemiological Weight Kininogen; vWD, Von Willebrand Disease; OGD, and clinical characteristics of Omani patients with PK and HMWK Oesophago-gastroduodenoscopy; CLO test, Campylobacter-like deficiency, focusing on abnormal bleeding in one child withPK organism test(for H Pylori; BPH, Benign prostatic hyperplasia; CVA, deficiency. Cerebrovascular accident; AF, Atrial fibrillation; CKD, Chronic Subjects and methods kidney disease We reviewed the files of patients investigated in Sultan Qaboos Introduction University Hospital (SQUH) between 2000- 2018, for prolonged The contact system includes FXII, FXI, prekallikrein (PK), and aPTT and were confirmed to have PK or HMWK deficiency. Data was high molecular weight kininogen (HMWK). This system is activated collected regarding their epidemiological characteristics, indication to in the presence of negatively charged surface, leading to activation of investigate for coagulation screening, screening laboratory results, FXI, followed by a chain of proteolytic reactions, resulting ultimately clinical phenotype and impact on their management. Assays for PK in thrombin generation and fibrin clot formation. and HMWK were based on commercially available factor deficient Fletcher’s and Fitzgerald’s trait plasma. This report focuses on the Lack of clinical bleeding in cases of contact factors deficiency is details of a child with PK deficiency who had significant mucosal supported by several reports, in which abnormally prolonged aPTT bleeding. was accidentally revealed on screening tests. Bypassing the role of PK and other contact activation system can take place in vivo through Results different mechanisms. First, activated platelets can trigger FXI Between 1999-2018, a total of eight patients were identified; two activation, independent of FXIIa. Second, tissue factor that is exposed males (25%), and six females (75%) from unrelated kind reds. Three by endothelial damage, can bind to FVIIa, leading to activation of FIX patients had PK deficiency; five patients had HMWK deficiency, in and FX. As a result, thrombin is generated, which causes fibrin and addition to more than 1000 patients who had factor XII deficiency (not FXIa formation. In addition, long chain polyphosphate can activate included in the report). Their age at diagnosis ranged between 2-80 the intrinsic pathway independently from the contact factors. These years (mean±SD: 26.3±26.7). Indications for coagulation screening mechanisms explain the lack of clinical bleeding in most patients with were preoperative assessment in five patients (62.5%), bleeding in two PK and other contact factors deficiency. On the other hand, clinical patients (25%) and family screening in one patient (12.5%). Median 1 bleeding has been rarely reported to be associated with PK deficiency. time from screening test to definitive diagnosis ranged from 3 to 8

Submit Manuscript | http://medcraveonline.com Hematol Transfus Int J. 2019;7(1):11‒15. 11 ©2019 Nazir et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Copyright: Prekallikrein and high molecular weight kininogen deficiency in Oman: a challenging diagnosis in mucosal 12 bleeding ©2019 Nazir et al. months. All but one patient had no history of abnormal bleeding. They data of patients with PK or HMWK deficiency. A 13 year-old child required no special preparation before surgery and post-operative with PK deficiency and a background diagnosis of Hashimoto thyroid course was unremarkable. it is presented with significant abnormal bleeding. Hypothyroidism was diagnosed at the age of 7 years, was treated with L- thyroxin, with Table 1 summarizes the epidemiological, clinical, and laboratory poor compliance. Table 1 Demographic clinical and laboratory data of patients with PK or HMWK deficiency 1 2 3 4 5 6 7 Sex F F M F M F F Age in years 14/ 5 9/2 17/11 49/48 84/80 37/34 21/21 (current/age at diagnosis) Diagnosis HMWK HMWK HMWK HMWK PK PK HMWK PTsec 10.5 10.4 11 10.6 11.2 10.5 10.7 INR 0.98 0.95 1.1 1.02 1 0.96 0.99 aPTT sec > 180 >180 >180 >180 >180 167.9 >180 aPTT mixing sec 41 41 40 38.4 39.6 33.6 33.6 Fibrinogen g/L 1.8 2.1 2.5 3.1 4.5 4.7 3.5 TT sec 14.9 15 14 14.5 14.8 19.5 16 0.456 PK (0.650-1.300)iu/ml 0.507 0.510 0.550 0.002 0.062 0.516 (0.530-1.450) 0.311 HMWK (0.640-1.320)iu/ml 0.001 0.008 <0.001 <0.007 0.884 <0.007 (0.500-1.360) F VIII 0.495-1.382 iu/ml 0.493 0.770 1.030 0.760 2.206 1.422 1.180 FIX 0.470-1.040iu/ml 0.564 0.825 0.940 0.846 1.737 1.102 1.100 FXI 0.560-1.500 iu/ml 0.558 0.554 0.568 0.580 0.565 0.563 0.570 FXII 0.640-1.290 iu/ml 0.640 0.840 0.780 1.220 0.747 1.315 0.870 vWD assay Normal Normal Normal Normal Normal Normal Normal Bleeding Bloody diarrhea None None None None Bleeding gums None Transfusion FFP Non None None None None None +ve Family history +ve -ve -ve -ve -ve -ve CVA BPH post open Comorbidity Bloody diarrhea OM None None prostatectomy None None IHD/AF CKD Multiple surgical No follow up No follow up 4 SVD, no Comments - - procedures without - since 2012 since 2011 bleeding bleeding Abbreviations: PK, prekallikrein; HMWK, high molecular weight kininogen; VWD, Von Willebrand disease; FFP, fresh frozen plasma; OM, otitis media; CVA, cerebrovascular accident; BPH, benign prostatic hyperplasia; IHD, ischemic heart disease; AF, atrial fibrillation; CKD, chronic kidney disease; SVD, spontaneous vaginal delivery At the age of ten years, she was referred from her primary hospital no focal tenderness and no organomegaly. There was no ecchymosis, to SQUH for further evaluation of a persistently prolonged aPTT with petechial rash or telangiectasia on her skin or oral mucosa, and her CNS recurrent bleeding. She gave history of easy bruising and prolonged examination showed no focal neurological deficits. Anthropometric vaginal bleeding that lasted for three weeks, in addition to four measurement showed that her weight was between 50th-75th centile episodes of hematemesis over a period of six months. There was no and height at 75th centile for age. X ray wrist showed her bone age to history of epistaxis, hematuria, hemarthrosis, or other complaints. Her be between 9-10 years. parents are non-consanguineous and family history was negative for Clinical presentation and laboratory tests at different admission bleeding tendency. On arrival to the hematology outpatient clinic, she episodes are summarized in Table 2. Laboratory tests were marked collapsed with hypovolemic shock and was immediately resuscitated for microcytic hypochromic anemia, normal platelet, normal total with normal saline boluses and shifted to PICU, where she received and differential WBCs counts. Iron profile showed iron deficiency. packed red blood (pRBCs) and fresh frozen plasma transfusion (FFP). Renal function tests, serum electrolytes and liver function test results Clinical examination revealed a well oriented adolescent girl, with were within normal levels. Her TFT initially revealed hypothyroidism marked pallor and no icterus. She was afebrile, blood pressure 87/49 (T4:5.2, TSH>100) that later normalized on L-thyroxin replacement. mmHg, heart rate 110 beats/min, capillary refill time (CRT) of 4 sec, Repeated coagulation screenings revealed normal PT, normal TT and and her peripheral pulses were feeble. Cardiovascular examination normal fibrinogen level, with a markedly prolonged aPTT on several revealed tachycardia with normal heart sounds and no gallop rhythm. occasions (111.7-164.1sec). Mixing study using 1:1normal plasma Chest examination was unremarkable, her abdomen was soft, with completely corrected aPTT, suggesting of factor deficiency.

Table 2 Clinical presentation and laboratory tests during different hospital admissions in a child with PK deficiency and abnormal bleeding Hospital 19/5/2016 30/8/2016 3/10/2018 17/10/2018 29/11/2018 admissions - History of - Hematemesis (3 episodes) - Dizziness and palpitation Hematemesis - Multiple dental vaginal bleeding, - Received PRBC Tx - Melena- No history of - OGD: edematous extraction and hematemesis - FFP Tx before OGD active bleeding hyperemic mucosa restoration - Hypovolemic - OGD: No evidence - Severe iron deficiency of 1st part of the Clinical under GA shock—PICU or source of upper GIT anemia duodenum presentation - Pretreated with admission bleeding -OGD:Normal upper GI - CLO test positive FFP Tx Fluid resuscitation - CLO test positive endoscopy, no source of -Received triple No post OP pRBC Tx Received triple therapy for bleeding therapy for H pylori bleeding FFP Tx H.pylori - Received PRBC Tx - Received pRBCs Tx Hb (g/dl) 7.9 11.3 4.4 4.5 6.4 HCT (0.35-0.45) 0.200 0.382 0.151 0.143 0.227 MCV (73-95fl) 71 73 62 63 70 MCH (24-33pg) 23 21 18 19 19 MCHC(31-35g/L) 32 29 29 31 28 Retic% (0.2-2%) NA NA 2.8 2.4 2.9 RDW (11.5-16.5%) 15.6 17.6 20.9 23 23 Platelets (103/mm3) 312 406 310 350 368

WBC (x103/mm3) 8.5 4.7 6.2 5.9 4 N 5.3 1.2 2.7 3 1.9 L 2.7 2.9 3.1 2.5 1.6 M 0.5 0.4 0.4 0.5 0.4 E 0 0.2 0 0 0 B 0 0.1 0 0 0 PT (9.8-11.6 sec) INR (0.91-1.09) 12 11.4 11.8 12.1 11.9 aPTT(24.2- 1.11 1.04 1.11 1.09 1.12 37.1sec) 119.8 157.2 111.7 164.1 90 TT (12.8-17.6sec) 16.2 16.8 14.1 16.2 14.5 Fibrinogen 1.7 2.4 1.8 2 2.4 (1.7-3.6g/L) aPTT mix@ 0 30.5 36.4 NA NA NA hour 32.3 37.4 NA NA NA aPTT mix@ 2 hours VWF Normal study Normal study LA screen LA screen (dRVVT) Lupus (APTT- LA 47.2 (N 30.4-51 anticoagulant sensitive > 130 sec) sec Coagulation factors(iu/ml) F VIII: C assay 3.149 (0.495-1.382) 1.083 FVIII chromogenic 2.515(0.493-1.430) 1.046 F IX:C 0.845(0.630-0.890) 0.943 F XI: C 0.746(0.520-1.200) 0.851 F XII: C 1.043(0.600-1.400) 1.123 Platelet function Normal assay HMWK 0.858 (2-4-17) (0.630-1.190 u/ml) Prekallikrein < 0.062 (0.530-1.450 u/ml) Serum 17 (6-35) NA 3 1 4 iron(umol/L) S. Transferrin 2.27(2-3.6) NA 3.5 3.05 3.61 Transferrin sat % 29.8(20-50) NA 3.4 1.3 4.4 Ferritinug/L 19 15 6 4 74 Occult blood +ve +ve +ve Negative +ve TFT (pmol/L) FreeT4 (12.6-21) 5.2 16.2 12.9 NA 21.1 TSH (0.51-4.3) >100 0.03 5.13 NA 1.55 Abbreviations: PICU, pediatric intensive care unit; pRBC Tx, packed red blood cell transfusion; FFP, Tx, fresh-frozen plasma transfusion; GA, general anaesthesia; OGD, oesophago- gastroduodenoscopy; CLO test, campylobacter-like organism test (for H pylori)

In view of her neglected hypothyroidism, next step in her can stimulate FSH receptors because of molecular similarity between evaluation was to rule out acquired VWD and other coagulation factor these two hormones (specificity spill over), leading to precocious deficiencies that are related to deficient production. The presence of puberty.3 This condition is reversible upon replacement therapy with lupus anticoagulant was also thought of, considering her primary thyroid hormones. It is mostly encountered in cases of prolonged diagnosis of Hashimoto thyroiditis. Surprisingly, her laboratory test hypothyroidism, which is usually reflected also on deceleration of results ruled out all of the speculated abnormalities. VWD workup linear growth, a finding that was lacking in the current case (height at was normal twice and coagulation factors assay were normal. Lupus 75th centile, and appropriate bone age). On the other hand, no more anticoagulant was negative, ruling it out as a possible cause of vaginal bleeding was seen after normalization of her hypothyroid prolonged aPTT. Thus, the next step was to test for HMWK and PK state, despite her persistently prolonged aPTT, arguing more in favor level. HMWK level was normal 0.858iu/ml (RR 0.630-1.190), while of being related to hypothyroidism. PK level was severely deficient (<0.062iu/ml (RR 0.530-1.450). In addition, the diagnosis of autoimmune thyroid disorder On follow up over a period of three years, her clinical course was (Hashimoto thyroiditis), provoked the need to rule out other marked with four hospital admissions: three times for management of autoimmune conditions that could be associated.4 Idiopathic severe anemia related to hematemesis and melena, and once for dental thrombocytopenic purpura, secondary antiphospholipid syndrome, extraction and restoration under general anaesthesia. Diagnostic and acquired hemophilia have been ruled out in the current case, based workup for GIT bleeding included upper and lower endoscopic on her normal platelet count, negative antiphospholipid antibodies, examination three times, that have been reported as normal, with and normal coagulation factors assay. no evidence of gastric/duodenal ulceration, or any evident source Progressively severe iron deficiency was notable in the current case of bleeding. Meckel’s diverticulum scintigraphy using (Tc99m- and it is related most probably to her acute and chronic blood loss. 125MBq) showed normal physiological radiotracer uptake, ruling The effect of iron deficiency anemia on hemostasis is double- faceted. out a local cause of her recurrent mucosal bleeding. CT angiography Anemia has been observed in vivo to produce a hypercoagulable state of the abdomen was requested to look for a source of GIT bleeding, through acceleration of platelet aggregation. Also, iron deficiency and was reported as normal. Before establishing the diagnosis of PK may promote thrombosis via elevation of plasma level of FVIII. On deficiency, she received FFP transfusion before dental extraction that the other hand, anemia is associated with a delay in the initiation resulted in normalization of APTT and no post-operative bleeding. of the coagulation cascade, leading to prolonged bleeding time, but Discussion improves viscoelastic properties and strength of the clot, and had no effect on coagulation time.5,6 As the patient did not tolerate oral iron, PK and HMWK deficiency are rare causes of persistently she was treated with intravenous ferrous sulfate infusion. Serum iron prolonged aPTT. In Oman, these disorders were identified in eight before replacement was 1 umol/L (Normal: 6-35), ferritin was 4 ug/L cases over a period of nine years. However, the true prevalence may (Normal:7-84), and transferrin saturation was 3.5% (normal 20-50%). be under estimated, in view of the asymptomatic nature of the defect On discharge, a different oral iron preparation (ferrous sulfate syrup) and the fact that these patients were referred for evaluation. Most was prescribed and she was encouraged on compliance. However, in cases were detected incidentally, on preoperative screening. Although view of repeated losses, her iron deficiency was difficult to correct. these conditions are not associated with significant bleeding, still they significantly impact clinical management of patients, in terms of costs Although severe PK deficiency is known to cause prolonged aPTT, of extensive investigation, and undue delay of surgical procedures. In it is rarely reported to be associated with clinical bleeding. Severe Oman, the average cost of extensive laboratory testing for coagulation PK deficiency is a rare disorder, till 2017, almost 150 cases have factors assay is 75USD/assay and vWD workup is around 150USD. been reported. (1)Rarely, clinical bleeding has been reported by some Furthermore, in the reported cases, there was a significant delay in authors to be associated with PK deficiency. In 2017, Antonio G and co- 7 planned surgical procedures between 3-6 months. authors, reviewed 106 papers on PK deficiency, and critically analyzed the few case reports that claimed an association with significant On the other hand, in the current report, the child who had significant bleeding diathesis. Among 100 cases with PK deficiency, ten cases bleeding imposed a diagnostic challenge. She was diagnosed with were reported to have clinical bleeding, representing 10%, similar to Hashimoto thyroiditis since the age of seven years. On presentation, bleeding cases in the current report (one out of eight; 12.5%). Reported her hypothyroid status was poorly controlled, as evidenced by low bleeding varied between mild (ecchymosis, epistaxis, oral mucosal free T4, and very high TSH levels. Before reaching the diagnosis of bleeding after surgery) to severe (presenting with hemarthrosis and PK deficiency, it was more plausible to rule out acquired vWD and requiring transfusion of pRBCs, or FFP). He argued that most of the other coagulation factor deficiency that are known to be associated reported cases had undergone surgical procedures (like tonsillectomy, with hypothyroidism. circumcision, delivery, and even hysterectomy) with no significant bleeding, thus excluding a bleeding tendency. He suggested that local Acquired vWD type 1 seems to be the most common reason factors or transient coagulation defects are the likely explanation for behind abnormal bleeding in patients with hypothyroidism. In those the occasional bleeding manifestations observed in those cases. In the cases, low levels of VWF are related to reduction in its synthesis current case, a local factor for recurrent hematemesis and melena could and/or secretion. Moreover, acquired vWD in cases of Hashimoto not be found, even after three endoscopic examinations, Mickel’s scan thyroiditis is reported independently of thyroid hormone levels, most and CT angiography of the abdomen. Transient coagulation defects, likely related to the rapid clearance of FVIII/VWF complex due to like acquired vWD, or other coagulation factors deficiency related to binding of non-neutralizing autoantibodies to VWF.2 her thyroid disorder were also ruled out. Prepubertal vaginal bleeding in the current case could be In few cases with PK deficiency, significant bleeding that viewed in 2 different ways: either as a manifestation of generalized responded to FFP transfusion was probably attributed toPK deficiency. coagulopathy or as a manifestation of precocious puberty related to A specific mutation that led to a bleeding phenotype was proposed as her hypothyroidism. Increased TSH levels in primary hypothyroidism

Citation: Nazir HF, Pathare AV. Prekallikrein and high molecular weight kininogen deficiency in Oman: a challenging diagnosis in mucosal bleeding.Hematol Transfus Int J. 2019;7(1):11‒15. DOI: 10.15406/htij.2019.07.00197 Copyright: Prekallikrein and high molecular weight kininogen deficiency in Oman: a challenging diagnosis in mucosal 15 bleeding ©2019 Nazir et al. a possible explanation. Nevertheless, molecular genetic testing have References been applied to few families so far, and these studies do not yet allow definite phenotype/genotype correlations.8,9 1. Zheng S, Just S, Brighton T. Prekallikrein deficiency. Pathology. 2016;48(6):634–637. The current case represented a diagnostic challenge, in view of 2. Koyama T, Fujimoto K, Shima M. Acquired von Willebrand syndrome the multiple sites of bleeding, severity of resulting anemia requiring associated with Hashimoto’s thyroiditis and subcutaneous mucosa– multiple transfusions, and no obvious local cause to explain bleeding. associated lymphoid tissue lymphoma. Intern Med. 2013;52(23):2661– Whether bleeding in the current case is related to PK deficiency is still 2663. unknown and might be added to previously reported symptomatic PK 3. Ghaemi N, Vakili R, Bagheri S. Precocious Puberty: An Unusual deficiency cases. Unfortunately, specific genetic testing for the exact Presentation of Hypothyroidism. International Journal of Pediatrics. mutation was not available in our laboratory. 2013;1(2):51–54. Conclusion 4. Squizzato A, Romualdi E, Büller HR, et al. Thyroid dysfunction and effects on coagulation and fibrinolysis: a systematic review. J Clin PK and HMWK are rare and most certainly underestimated in Endocrinol Metab. 2007; 92(7):2415–2420. Oman. Most cases were detected upon investigations for prolonged 5. Roeloffzen WW, Kluin–Nelemans HC, Bosman L, et al. Effects of red aPTTon pre-operative screening. However, they have asignificant blood cells on hemostasis. Transfusion. 2010;50(7):1536–1544. impact on costs related to extensive laboratory testing and delay of planned surgical procedure. Additionally, some cases with clinical 6. Livesey JA, Manning RA, Meek JH, et al. Low serum iron levels bleeding impose a diagnostic challenge. Further studies to explore are associated with elevated plasma levels of coagulation factor VIII possible genotype-phenotype relation are needed. and pulmonary emboli/deep venous thromboses in replicate cohorts of patients with hereditary haemorrhagic telangiectasia. Thorax. Conflict of interest and sources of funding 2012;67(4):328–333. 7. Girolami A, Cosi E, Ferrari S, et al. Critical Analysis of the Patients Funding source: Authors have no financial relations relevant to with Congenital Prekallikrein Deficiency and a Purported Bleeding this article to disclose. Tendency. J Mol Genet Med. 2017(1)1:9 Conflict of interests: Authors have no conflict of interests relevant 8. Girolami A, Scarparo P, Candeo N, et al. Congenital prekallikrein to this article to disclose. deficiency. Expert Review of Hematology. 2010;3(6):685–695. 9. Girolami A, Ferrari S, Cosi E, et al. A structure-function analysis in Acknowledgments patients with prekallikrein deficiency. Hematology. 2018;23(6):346– None. 350.